Valve mechanism for ai r-compressors



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E REYNOLDS.

VALVE MECHANISM FOR AIR GOMPRESSORS.

Patented Feb.'21, 1888.

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VALVE MECHANISM FOR AIR GOMPRESSORS. No. 378,336. Patented Feb. '21, 1888.

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' UNITED STATES EDXVIN REYNOLDS, OF MILNAUKEE, WVISCONSIN.

VALVE MECHANISM FOR AlR=COlVlPRESSORS.

SPECIFICATION forming part of Letters Patent No. 378,336, dated February 21,1888.

Application filed May 3, 1887. Serial No. 236,980. (No model.)

To all whom it may concern.-

Be it known that I, EDWIN REYNOLDS, of Milwaukee, in the county of Milwaukee and State of \Visconsin, have invented certain new and useful Improvements in Valve Mechanism for Air-Compressors, Blowing Engines, and Lihe Machinery, of which the following is a specification.

My invention relates to certain improvements in valve mechanism of air-compressors, blowing-engines, and like machinery, whereby the action of the delivery-valve is rendered automatic and its time of opening is made dependent upon the relative pressures in the aircylinder and in the receiver or reservoir to which the air is delivered, its time of closing being positively determined by connection with other moving parts of the machine.

In the accompanying drawings, Figure 1 is a side elevation of one end of an air-cylinder of an air-compressor, showing my improved valve mechanism, the ports and gates being indicated in dotted lines; Fig. 2, an end elevation of the same; Figs. 3 and 4., views illustrating the construction and operation of the delivery valve.

Heretoiore flap n valves and puppet-valves have been employed in air-compressors, blowing-engines, and analogous machinery to permit and control the passage of air from the air-cylinder to the receiver or reservoir, and such valves are automatic in so far as they open when the pressure of air in the cylinder exceeds that in the receiver sufliciently to overcome the latter, the weight of the valves, and the additional pressure of the springs or weights employed to return the valves to their seats; but the action of such valves is uncertain and noisy, and their use involves the expenditure of power over and above that actually necessary to the amount required to raise the pressure in the cylinder sufficiently above that in the receiver to overcome the resistance of the weight of the valves and the resistance of their springs. The use of such valves also limits the working speed of the machine.

Slide-valves and oscillating or rolling valves have also been employed heretofore as delivery-valves for this class of machines; but in such cases the action of the valves has been positively determined by connection with other moving parts of the machine, so that the time of their opening has had no reference to the relative pressures in the air cylinder and receiver, except as determined by positive adjustment of the operating mechanism, the delivery-valve opening either before or after the pressure in the cylinder equaled the pressure in the receiver, the receiver-pressure varying above or below the point at which the valve is set to open. In either case a needless expenditure of power is involved and the efficiency of the machine is limited to certain fixed conditions and requirements, thus making it impossible for any given machine to 0p crate with a satisfactory degree of economy or efficiency, eircept under the precise and fixed conditions for which that particular machine was originally designed.

In the various forms of valve mechanism heretofore employed for'this class of machines there has also been an excessive amount of clearaneein the air-cylinder, resulting in waste of power. By my invention these difficulties and defects are obviated and the clearancespace is reduced toa minimum. The deliveryvalve is so constructed and arranged as to open automatically and instantaneously to its full capacity when the pressure in the air-cylinder is nearly or quite equal to that in the receiver. The point of relative pressures at which the opening of the valve shall take place may be determined in constructing the machine,or by very simple means may be varied at any time, as desired.

The invention is susceptible of embodiment in different forms, the annexed drawings and the following description disclosing the construction and arrangement which I consider most advisable.

In said drawings, A indicates the air-cylinder, and B the head thereof, containing the valve-chambers for one inlet-valve, G, and one delivery-valve,D. In this head are also formed the usual passages to admit air to the inletvalve and to connect the delivery-valve chest with the receiver. Suitable portopenings (indicated by dotted lines) are provided .be-

tween the valvechambers and the interior of 100 the cylinder, which ports are opened and closed by the valves atthe proper times, as

herein explained. The valve-seats are brought as close as possible to the inner face of the head B, thus reducing the clearance-space to the smallest practicable amount.

The valves 0 and D, I make preferably of the rolling or oscillating type, though I do not mean to be understood as confining myself thereto, it being apparent that any one of a large variety of types may be selected and used in carrying out my invention.

Motion is communicated to valves 0 and D preferably by means of a wrist-plate, NV, and connecting-rods R R, the rods connecting with suitable arms fastened to the valve-stems, as.

plainly shown in Fig. 1. The wrist-plate receives motion from an eccentric on the main shaft of the-machine through suitable connection, or may be actuated in any other convenient manner. \Vhen a wrist-plate is employed, it is carried by astand or an arm bolted to the side of the cylinder.

The connection between wrist-plate \V and inlet-valveO is at all times positive, and any motion of the wrist-plate imparts corresponding motion to the inlet-valve. The action of inlet-valve O is therefore simply that of any ordinary rolling slide-valve, the times of opening and closing being controlled by the wellknown action of the wrist-plate.

The connection between the wrist-plate NV and the delivery-valve Dis made by means of a rod, B, slotted or forked to receive the pin a of the actuating-arm of the valve, and is positive only at such time as the rod R is moving toward the cylinder-head and acting upon the valve to' close it. \Vhen the motion of the wrist-plate is reversed, the slotted or forked end of rod R permits the reverse motion of the wrist-plate and rod R to take place, while the delivery-valve remains closed and is held in position by a hook or catch, L,

until such time as it is automatically released and allowed to open.

The mechanism by which delivery-valve D is held closed until the proper moment and then automatically released and permitted to open is more clearly illustrated in Figs. 3 and 4. As shown in said figures and also in Fig. 1, an arm, E, is keyed on or otherwise attached to the stem of valve D, said arm at or near its outer end carrying a pin, F, and a block, G. To said arm E is also attached, by suitable pin and rod, aweight, H, working in a dash-pot, I.

J indicates a fixed pin, on which is pivoted the hook or catch L, above referred to, which hook is provided with a tail-piece, M, and is pressed downward by a spring, N, whereby the hook L is pressed forward and caused to engage with block G.

0 indicates asmall supplemental cylinder provided with a piston, P, and piston-rod S, said rod reaching nearly to tail-piece M of hook L when the delivery-valve is closed and held closed by the hook, the piston-rod being of such, length that a short movement of the piston P will cause it to bear against tail-piece M, and that a further movement of said piston will cause tail-piece M and hook L to move and release the valve, which is then instantaneously opened to its full extent by the falling of weight H.

A pipe, T, connects one end of cylinder 0 with the receiver, and a similar pipe, U, connects the other end of said cylinder with the end of air-cylinder A, so that on one side of piston P there is always the pressure of the air in the receiver, and on the other side there is whatever pressure may be in the air-cylinder.

The action of the mechanism is as follows: As the wrist-plate NV and rod R move toward head B, the delivery-valve D is closed positively, and as the extreme limit of motion of the wrist-plate is reached hook L is thrown forward by spring N, engages with block G, and holds the valve closed, as shown in Fig. 3. As the motion of wrist-plate WV and rod R is vreversed, the forked end of said rod slides back upon and independently of the pin a, and consequently allows the delivery-valve D to remain closed until such time as the pressure in the air-cylinder and consequent pressure on the side of piston P, connected with the air-cylinder by pipe U, is sufficient to over come the pressure on the opposite side of piston 1?, connected with the receiver by pipe T,

when piston P will move and carry with it the rod S, causing the latter to strike against the tail-piece M and to move it, thereby dis engaging hook L from block G. Vhen this disengagementtakes place,the action of weight H simultaneously opens delivery-valve D to its fulllextent, as shown in Fig. 4, and it remains thus open until again closed by the action of wrist-plate W and rod R.

The complete action of the valves on one v end of the air-cylinder may be briefly described as follows: At the beginning of the stroke the piston in the air'cylinder A is at the end closed by head B and just beginning to move toward the opposite end of the cylinder. At the same time the delivery-valve is closed and the inlet-valve commences to open,opens very quickly, and remains open until the piston reaches the opposite end of its stroke. Just as the piston begins its return-stroke theinletvalve is closed, and it is retained against its seat by the receiver-pressure on its back. As the piston in air-cylinder A moves toward head B, the air before it is compressed until it equals the pressure in the receiver,when the movementof piston P in the small supplemental cylinder 0 disengages the retaininghook L and allows delivery-valve D to be opened by the action of' the weight. At the time of its opening the delivery-valve is in equilibrium, so that the amount of power re quired to open it is very small.

It is obvious that a vacuum dash-pot may be employed instead of a weight to close the valve, such construction being the same as represented in Fig. 1, except that the piston or plunger of the dash-pot will be lighter and more closely fitted, and that the openings rep resented in the bottom of the dashpot will be omitted.

When the delivery-valve is open, it offers no resistance to the passage of the airfrom the air-cylinder into the receiver, and hence in1- poses no additional work on the motive power.

In building the machine the precise point of relative pressure in the receiver and air-cylinder at which the delivery-valve shall open may be determined and fixed by the cross-section or area given the rod S of piston P, it being apparent that as its diameter is increased the effective area of that face of piston P with which it connects will be decreased, and that to such extent the opposite face will be greater in pressure area; hence the pressure on such opposite face will exceed in a greater or less degree the pressure on the face from which rod S proj ects,and consequently the delivery-valve will open just a little before the pressures in the air-cylinder and receiver are equalized. The same result may be attained by making the piston P in two sections of different diameter, and the relative areas may, if desired, be reversed, so that the valve shall open only when the cylinderpressure slightly exceeds the receiverpressure.

In order to permit the control and variation of the point of relative pressures at which the delivery-valve shall open, a spring or weight may be applied to offer a greater or less resistance to the movement of the piston toward or against tail M of latch L. If spring-pressure be employed for this purpose, the spring N may be utilized and other spring orsprings rendered unnecessary, a set-screw, Q, being arranged to bear upon and vary the force of the spring, as indicated in Fig. 4. If a weight be employed, it may be conveniently applied to an extension of tail M and made adjustable thereon, as shown in Fig. 8 in dotted lines. Under both these arrangements, with the piston area slightly in favor of the air-cylinder pressure, it is possible to vary the point of opening so that it shall be,when the two press ures are exactly equal or when the cylinder is slightly below or slightly above the receiverpressurc, a range adequate for all conditions that can arise in the use of such machinery;

but obviously the range may be increased, as

desired.

As before stated, the details of construction are susceptible of considerable variation, and therefore I do not restrict myself to the precise form or arrangement of parts shown. The weight H, for opening valve D, may obviously be replaced by a spring, though the weight is preferred, as shown in Fig. 4. In other words, the only thing essential is that the valve shall be self-opening or capable of openingautomatieally when released by the catch instead of being moved through connection with other moving parts of the machinery or by fluidpressure.

It is likewise apparent that a flexible diaphragm may be used instead of the sliding piston P, the two being well-recognized equivalents for such uses, and that instead of being slotted to straddle pin a the rod It may pass through the same, in which case the pin would need to be swiveled in the valve-arm. The construction shown and described is, however, preferred.

Having thus described my invention .,what I claim is- 1. In an air'compressor, blowing-engine, or

like machine, the combination of a self-open ing delivery-valve, a rod having a sliding connection with said valve and serving, when moved in one direction, to close the same, a catch adapted to hold the valve closed, and a movable stem or trip subject to the opposing pressure of the fluid in the receiver and inv the compressor and arranged to act upon the catch, whereby the catch is caused to hold the delivery-valve closed until the trip is moved by the pressure of the fluid in the compressor overcoming the pressure or resistance of the fluid in the receiver and then to release the valve, thereby permitting the latter to open.

2. In combination with the delivery-valve of an air-compressor, blowing engine, or like machine, a connecting device between said valve and a moving part of the machine for closing the valve, a catch or hook for holding said valve closed, aweight or spring for opening said valve when released by the catch, and a trip controlled by the pressures in the aircylinder and in the receiver for releasing the catch, whereby the delivery-valve is released and opened when a certain predetermined relation is established between the receiver and cylinder pressures.

3. In an air-compressor, blowing-engine, or like machine, the combination of a self-opening delivery-valve, a catch for holding said valve closed, a rod or connection extending from a moving part of the machine to the valve and serving to close the latter, a cylinder communicating at opposite ends with the air-cylinder and the receiver, and a piston arranged within said cylinder and serving to release the catch when the pressure on the face of the piston receiving air from the air-cylinder overcomes the pressure on the face receiving air from the receiver.

at. In combination with the delivery-valve of an air-compressor, blowing-engine, or like machine, a catch adapted to engage said valve and hold it closed and a trip for releasing said catch actuated and controlled by the relative pressures in the aincylinder and in the receiver.

5. In combination with the delivery-valve of an air'compressor, blowing-engine,or like machine, a catch adapted to engage and hold said valve out of action, a trip for releasing said catch actuated and controlled by the relative pressures in the air-cylinder and in the receiver, and an adjustable resistance for varying the point of relative pressures at which the trip shall release the catch.

6. In combination with. aircylinder A, head B, provided with valve-chambers, inlet-valve O, delivery-valve D,wrist-plate W, rod R,connecting valve 0 with the wrist-plate, slotted rod R, connecting valve D and the wrist-plate, arm E, attached to stem of valve D and provided with block G, hook or catch L, provided with tail M, cylinder 0, piston P, arranged within said cylinder, rod S,extending from the piston to a pointjust beneath tail M, and pipes T and U, respectively connecting opposite ends of cylinder 0 with the air-receiver and the air-cylinder.

7. In an air-compressor, blowing-engine, or

like machine, the combination of a deliveryvalve provided with a weighted arm and with a projecting block or lug, a pivoted catch adapted and arranged to engage with said lug and to hold the valve closed, a cylinder communicating at its opposite ends with the airreceiver and air-cylinder, and a piston located within said cylinder and serving to release the catch when the pressure from the air-cylinder reaches a prescribed relation to that from the receiver.

8. In an air-compressor, blowing-engine, or like machine, the combination,with the delivery-valve D, of two arms rigidly attached to its stem, a pin, a, carried by one of said arms,

a slotted rod connected with a moving part of the machine and straddling'said pin, a pivoted 3o catch, L, adapted to engage with the second arm and provided with a tail, M, a spring, N,

,bearing upon said tail, cylinder 0, communicating at opposite ends, respectively,with the scribed tripping mechanism, spring N,and set- 5' screw Q, bearing upon said spring and serving to vary the resistance of the catch to the force exerted by the piston of the tripping mechanism.

In witness whereof I hereunto set my hand 50 in the presence of two witnesses.

EDWIN REYNOLDS.

Witnesses:

ALBERT HOPPIN, IRVING H. REYNOLDS. 

